Exploring subobjects while fetching observables (typescript/angular)

When retrieving JSON from an API into an Angular service, I am working with a collection of objects structured like this:

{
  "data": {
    "id": 1,
    "title": "one"
  },
  "stats" : {
    "voteCount": 8
  }
}

I am particularly interested in the 'data' part, as I intend to submit it back in a reactive form in Angular. To achieve this, I need the observable to be a collection of objects containing only the id and title:

export class SimpleIssue {
  id: number;
  title: string; 
}

In my Angular service, I retrieve the data using the following method:

getItems(): Observable<SimpleIssue[]> {
    return this.http.get(this.apiUrl + 'simpleissues/')
        .map((response: Response) => <SimpleIssue[]> response.json())
        .do(thedata => console.log('all: ' + JSON.stringify(thedata)))
        .catch(this.handleError);
}

I have attempted to modify the response handling by using response.json().data or adding an additional .map like this:

.map(blah => blah.data)

However, these attempts have not been successful. Interestingly, if I import the data as an 'any' type, I can use {{ myItem.data | json }} and retrieve the expected information for each collection object.

Is there a way to address this issue and correctly send different view models for each view, or is there a fundamental concept that I am missing?

Thank you

Answer №1

Although untested, the following code snippet is likely to be effective in your scenario:

fetchItems(): Observable<SimpleIssue[]> {
    return this.apiService.fetchData(this.apiUrl + 'simpleissues/')
        .map((response: Response) => <any[]> response.json())
        .map((data: any[]) => data.map(item => item.data))
        .do(items => console.log('Retrieved items: ' + JSON.stringify(items)))
        .catch(error => this.handleFetchError(error));
}

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